U.S. Pat. Nos. 3,635,356; 3,716,146; 3,760,954 and 3,888,358 all relate to typical metal wearplates or bearing blocks which are utilized in the pinholes of coupler shanks. Such bearing blocks are not resilient but rigid, are usually bulky and cumbersome, and difficult to handle and maintain in position within the pinhole of the coupler shank. The invention is directed to the provision of a simple, highly approved wearplate and mechanism for maintaining it captured within the pinhole of a coupler shank.
Briefly stated, the invention is in a coupler used in coupling a plurality of cars together in tandem. The coupler comprises a shank having a butt end adjacent which is located a pinhole that extends transversely through the shank for receiving a pivot pin that pivotally mounts the shank. The pinhole includes an elongated recess which is disposed in the backside of the pinhole closest the butt end of the shank and which extends longitudinally of the pinhole. A non-metallic replaceable wearplate, composed of an ultra high molecular weight polymer, is disposed in the recess between the butt end of the shank and pivot pin which extends through the pinhole. Means are provided for maintaining the wearplate captive in the recess.